Seeing that flight made the Collector realize the draconid had been significantly limiting its strength, allowing the Collector to strike it to sate its own desires. It was the same manner in which the Collector itself would allow certain specimen that it believed to be worthy leeway within which to show further their battle prowess and worth before consuming them for the Collective.
In essence, an act of mercy. Yet, the Collector could sense that this mercy, this act of leaving it alive, was bestowed primarily with the emotion of respect behind it.
Respect of the Collector's strength, and respect that it could reach further heights of power.
At the same time, this was not solely the reason for the draconid specimen's actions. The specimen knew of the Collector, or at the very least possessed some ideation of the Collector's strength and potential to grow already.